Tehran - Supporters of opposition leader Mir-Hossein Moussavi planned to hold another protest Tuesday in Tehran, opposition circles said.

The gathering was to be held at the Vali-Asr square in downtown Tehran, the same venue where President Mahmoud Ahmadinejad on Sunday celebrated his re-election victory.

Hundreds of thousands attended a protest rally on Monday in Tehran which was the biggest since the 1979 Islamic revolution.

Some even said the number of demonstrators exceeded 1 million despite a ban by the interior ministry and warnings by police.

Several demonstrators were injured during Monday's demonstrations and there were reports of one person killed, which could not be verified.

Tehran radio reported that seven people were killed after an attack on a military post near the rally site but it is unclear whether the incident had anything to do with the demonstrators. The incident was also not yet reported by other local news sources.

The office of Mohammad-Ali Abtahi said meanwhile that the former vice-president of Mohammad Khatami was arrested. Abtahi is member of the anti-Ahmadinejad camp. No further details are yet available. (dpa)